Over the past several years, a significant increase in recording density in thin-film magnetic recording discs has been achieved, and there is a continuing effort to increase recording density further. Reducing the head-to-disk spacing, or the flying height, is one of the more effective ways to achieve a higher density on a magnetic rigid disk. As the read/write head is moved closer to the disk, there is less overlap of voltage signals in adjacent magnetic domains in the disk, with a corresponding increase in recording density. However, to have read/write heads flying over the disk surfaces at sub-microinch spacing, the topography of the disk surface must be very uniform. Current polishing methods for Ni/P plated disks commonly employ polishing slurries which are primarily mechanical in action, containing micron- or submicron-sized abrasive particles and a chemical accelerator, typically Al(NO.sub.3).sub.3 (aluminum nitrate). These methods have produced surfaces having roughness averages (RA) of about 0.4 nm (4 .ANG.). However, methods of polishing such surfaces to still greater smoothness are sought.